Reasons for drywall joints cracking
Why drywall joints crack?
Building shifting, temperature and moisture changes, even wind blow on a house cause stresses to drywall joints. Crack happens if the joints are not strong enough to resist the stresses. There are mainly two reasons for drywall joint cracking:
First, drywall boarding issues.
Second, drywall taping problems.
Drywall boarding issues
Joints above windows and doors
Never line up joints neither on walls nor ceilings
Joint right on the corner above window and doors
Reasons for drywall joints cracking:
Most of cracks occurred on the joints above windows and doors.
Try your best To avoid to have joints around high stress areas.
Joint right on the corner above window and doors
Never line up joints neither on walls nor ceilings
Joint right on the corner above window and doors
Why drywall joint crack?
The worst is joint right on the corner above windows and doors!
Never line up joints neither on walls nor ceilings
Never line up joints neither on walls nor ceilings
Never line up joints neither on walls nor ceilings
A common mistake for drywall boarding is to line up the joints. Especially on ceilings. Avoid to line up butt joints on walls as well.
Joint right on the corner of load bearing wall
Drywall sagging caused by lack of screws on ceIling
Never line up joints neither on walls nor ceilings
Most of ceiling joint cracks are around load bearing wall. Especially on corners.
Joint is on the very edge of studs or joist
Drywall sagging caused by lack of screws on ceIling
Drywall sagging caused by lack of screws on ceIling
Lack of backing is a common reason cause joint crack. Joint is on the very edge of studs or ceiling joist. Screws on the very edge of the drywall sheet can not fasten drywall to the studs or joist properly.
Drywall sagging caused by lack of screws on ceIling
Drywall sagging caused by lack of screws on ceIling
Drywall sagging caused by lack of screws on ceIling
Cracks on ceiling joints often caused by drywall sagging. Especially flat joint along ceiling joist without enough screws.
Taping problems
No mud filled in the joint
Gap behind mesh tape is empty
No mud filled in the joint
Cut the cracked joints open, almost 100% of them, there was no mud filled in the joint gaps. It is most common reason for drywall joint crack.
Bedding mud too thin
Gap behind mesh tape is empty
No mud filled in the joint
Using bazooka or banjo box to apply paper tape, there is only a thin layer of mud in the back of the tape. There is no mud in joint gaps.
Gap behind mesh tape is empty
Gap behind mesh tape is empty
Gap behind mesh tape is empty
Without pre-fill, even using mesh tape, the cavity in the joint is not filled with mud.
Paper tape cracked
Plastic shrink crack
Gap behind mesh tape is empty
Because there is no mud filled in the gap, only a layer of paper tape could not resist the stress on the joint, that was why the joint cracked.
Mesh tape crooked
Plastic shrink crack
Plastic shrink crack
Without pre-fill, even mesh tape with fast set mud cracks.
Plastic shrink crack
Plastic shrink crack
Plastic shrink crack
There is plastic shrinkage when temperature and moisture change. If the layer of mud on top of the tape is too thick, we have very good chance to have a crack.
How to prevent Cracks
Install drywall sheets properly is very important to prevent crack!
- Avoid to have joints above windows and doors.
- Avoid joints line up.
- Install additional backings.
- Put enough screws. Make sure every sheet of drywall is installed properly.
For more information about how to install drywall:
Pre-filled drywall joint
When the joint is filled with mud, the two sheets of drywall are welded in to one piece. The joint is stronger than just a piece of paper tape covering the joint with a hollowing cavity in the back.
Unfortunately, some tapers skip the process of pre-fill for some reasons.
